Vegetation and Topographic Factors Affecting SOM, SOC, and N Contents in a Mountainous Watershed in North China
Round 1
Reviewer 1 Report
Row 70 - Beijing (area, 889.02 hm2 ) – hm or km ??
Row 72 - Mountain cinnamon soil is the major soil type in the study area. There is a 73 a small amount of brown mountain soil – Cinnamon soil or brown soil by which soil classification – please give information about soil type – according to WRB or Soil Taxonomy – for example, Cambisols or Inceptisols or other.
Row 100 - The pH was determined at a soil and water ratio of 2.5:1 via a 100 potentiometer method. SOM and SOC were determined using a potassium dichromate sulfate oxidation-volumetric method – please give ISO method or citation.
Give the name of the soil types according to WRB or Soil Taxonomy in the studied area.
Author Response
Dear Reviewers,
Thank you very much for your time involved in reviewing the manuscript.We have written all the replies in detail in the attachment.Please see the attachment.
Sincerely,
The Authors
Author Response File: 
Author Response.pdf
Reviewer 2 Report
First of all, the title of the manuscript does not fit to the content. Authors analyzed only content of organic carbon and nitrogen, however from two these elements only nitrogen is a nutrient for plants. Content of nutrients in the soil organic matter depends on many factors and soil organic matter can not be a measure of the nutrients. It is impossible to analyze nutritional status of these soils based only on the nitrogen content.
What was included in the analysis as a soil organic matter? It is not clear from the Methods section. Does it include forest litter layer? If so, the data on thickness and stock of forest litter should be given separately from the total soil organic matter.
And it is necessary to describe methods of soil organic carbon and soil organic matter determination. It is important because on the Fig.3 soil organic carbon content on the sample site D3 comprises about 67% of the soil organic matter. It is too much.
Description of these methods also needs to assess the correctness of the correlation assessment between SOM and SOC.
Discussion of the received results is very poor. In the subsection 4.2. authors does not compare their results with others so it is not clear why they think that the content of SOM and TN in the study area is very high. It is necessary to decode which forests are on the plots A1, A3, B1, A4, B2, B4, C5, and C7 and explain what are the common for these plots and what differ them from others.
In the subsection 4.3.: This research does not indicate that "altitude is a key factor affecting the physical and chemical properties of the soil" (Lines 257-258) because authors did not study physical soil properties and analyzed only few chemical properties. Results of this study also does not show that "vegetation regulates the microbial community structure and diversity" (Lines 262-263) because authors did not study microbial communities of the sample sites. It is impossible to make such conclusions based on the results of this study.
Conclusion section need to be rewrited because it does not include the conclusion based on the obtained results and discussion. It only repeats the results. Conclusion should explain the contribution of the study to the current knowledge in this field.
The minor remarks are:
1. Lines 31-32: Why athors think that C is a crusial element for forest ecosystems?
2. Line 73: It is necessary to give the reference on soil classification used to determine these soil types. And it should be good to give equivalent soil names according to WRB for better understanding of readers.
3. Line 179 and Line 186: Which soil metal content athors meant in these cases?
4. Lines 204-205: The last sentence in this paragraph is not clear.
5. Line 230: "undeground roots of aboveground plants". This phrase looks incorrect. Plant consist of shoot (aboveground part) and root (belowground part). So the aboveground plant does not sound good. It will be better to tell simply undeground roots of plants.
6. Lines 230-231: Stock of the litter depends on quantity and quality of the annual aboveground litterfall. So that roots alone can not explain different ammount of litter in these forests.
7. Line 236: What is the "biological nitrogen"? What is the difference of this nitrogen from nitrogen contained in soil organic matter?
Author Response
Dear Reviewers,
Thank you very much for your time involved in reviewing the manuscript.We have written all the replies in detail in the attachment.Please see the attachment.
Sincerely,
The Authors
Author Response File: Author Response.pdf
Reviewer 3 Report
The work refers to some results with interest!
Material and Methods
Line 88: “… were taken at intervals of 5 minutes”. What is the relevance of this information?
Results
Line 124-130: In my opinion, reading would be easier if you followed the order H, D, E, as this is the sequence in Figure 2. It can create some confusion when reading between the text and the figure.
Line 133 – 135: “The elevation and slope of the study area were 226.2-762.4 m and 5-38 °, respectively. The forest types of arbor forests in the basin could be divided into four categories: Conif-134 erous Forest (Type I), coniferous and broad-leaved mixed forest (Type II), broad-leaved forest (Type III), and broad-leaved mixed forest (Type IV).” This information should pass to Material and Methods.
Line 153: For average values, two decimal places is sufficient!
Author Response
Dear Reviewers,
Thank you very much for your time involved in reviewing the manuscript.We have written all the replies in detail in the attachment.Please see the attachment.
Sincerely,
The Authors
Author Response File: Author Response.pdf
